Signals are transmitted in a wide range of formats, voltage levels, and speeds (e.g., digital, analog, TTL, MECL, T1, fiber optic, etc.). A signal in one format may be incompatible with a signal in another. Therefore, different procedures may be required to process different signal formats. Different procedures may require the use of different processing equipment. Such equipment may be expensive, and the operator may be required to receive extensive training in order to be able to operate the equipment.
U.S. Pat. No. 5,113,186, entitled "APPARATUS FOR CONVERTING AN ALTERNATE MARK INVERSION SIGNAL TO UNIPOLAR SIGNALS WITH FREQUENCY DEPENDENT AMPLIFICATION," discloses a device for converting an alternate mark inversion (AMI) signal into three different unipolar signals. An AMI signal has three logic levels (i.e., a reference level, a logic one level which is a voltage above the reference level, and a logic zero level which is a voltage below the reference level. The device of U.S. Pat. No. 5,113,186 provides a first signal consisting of the logic one components of an AMI signal, a second signal consisting of the logic zero components of the AMI signal where the logic zero level is converted to the logic one level, and a third signal consisting of both the logic one levels and the logic zero levels of the AMI signal where the logic zero level is converted to the logic one level. U.S. Pat. No. 5,113,186 does not process multiple signals as does the present invention and does not include the other features of the present invention. U.S. Pat. No. 5,113,186 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 5,248,969, entitled "PHASE COMPARING AND CMI/NRZ DECODING APPARATUS," discloses a device for producing a clock pulse at the center of the CMI data. U.S. Pat. No. 5,248,969 does not process multiple signals as does the present invention and does not include the other features of the present invention. U.S. Pat. No. 5,248,969 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 5,657,017, entitled "TELEMETRY BI-PHASE-LEVEL TO NON-RETURN-TO-ZERO-LEVEL SIGNAL CONVERTER," discloses a device for converting an RZ signal to an NRZ signal. U.S. Pat. No. 5,657,017 does not process multiple signals as does the present invention and does not include the other features of the present invention. U.S. Pat. No. 5,657,017 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 5,892,797, entitled "SYSTEM AND METHOD FOR RECOVERING DATA ENCODED USING MANCHESTER CODE AND OTHER BI-PHASE LEVEL CODES," discloses a device for and method of recovering a data signal and a clock signal from a data signal encoded in a digital code. U.S. Pat. No. 5,892,797 does not process multiple signals as does the present invention and does not include the other features of the present invention. U.S. Pat. No. 5,892,797 is hereby incorporated by reference into the specification of the present invention.